QTM 385 - Experimental Methods

Lecture 06 - Texts for Discussion and More

Danilo Freire

Emory University

Hi, there! 👋
Tudo bem? 😄🇧🇷

Brief recap 📚

Last time, we saw that…

  • Regression in R: Covered adding covariates with lm_lin(), centring, and sub-group analysis with interaction terms using lm_robust.
  • Hypothesis Testing: Covered different types of null hypotheses: sharp null and null hypothesis of no average treatment effect; confidence intervals, type I and type II errors
  • Statistical concept of sampling variability, how it relates to sampling distributions, and how it affects the interpretation of experimental estimates
  • Randomisation Inference: Introduced, with the ri2 package, which uses the randomizr package.
  • Demonstrated RI with two examples, including one about female council heads and the other about runoff elections.
  • Real Experiment: Analysed a paper using linear regression models as well as Randomisation Inference

Today, we will…

Group Work 🤝

What I have in mind…

  • Now that you have your groups, I’d like you to start working on your pre-analysis plan
  • I’ll give you some time to discuss your ideas and start writing your plan
  • My plan is that you should slowly think about your final project, one step at a time
  • What do you think about having two weeks to write the following:
    • Submit at most 2 paragraphs summarising an experiment that you want to develop in this course. At minimum, your summary should include a research question, why the question is important, and a rough sketch of how you plan to answer the question.
  • In three weeks:
    • Write a title and abstract for a paper you imagine writing based on your proposed experiment. Assume that your findings align with your theoretical predictions. Remember to establish why the findings matter for your intended audience.
  • In four weeks:
    • Outline your pre-analysis plan. Your outline should include sections on the research question, the experimental design, the data you will collect, and the analysis you will conduct.

What I have in mind…

  • In five weeks:
    • Use Quarto and DeclareDesign to write your report and simulate your experiment
  • In six weeks:
    • Revised outline, now including a new section titled “Potential Threats.” In this section, diagnose threats and briefly describe potential countermeasures. This new section should discuss false positives, statistical power, demand effects, noncompliance, spillover, and attrition.
  • In seven weeks:
    • Revised outline, now included a new section on “Heterogeneous Treatment Effects.” In this section, discuss how you might explore heterogeneity in treatment effects. This section should include a discussion of how you might use covariates to explore heterogeneity.
  • In eight weeks:
    • I will give you feedback on your outline and provide you with the simulated data for your experiment.
    • You will have two weeks to write your final report.
  • Last week of class:
    • You will present your findings to the class.

R packages 📦

fabricatr

  • fabricatr is a package that helps you simulate data for your experiments